As wireless communications technologies evolve, wireless communications systems become increasingly sophisticated. As such, wireless communications protocols continue to expand and change to take advantage of the technological evolution. As a result, to maximize flexibility, many wireless communications devices must be capable of supporting any number of wireless communications protocols, including protocols that operate using different communications modes, such as a half-duplex mode or a full-duplex mode, and including protocols that operate using different frequency bands. Further, the different communications modes may include different types of RF modulation modes, each of which may have certain performance requirements, such as specific out-of-band emissions requirements or symbol differentiation requirements.
Additionally, portable wireless communications devices are typically battery powered, need to be relatively small, and have low cost. As such, to minimize size, cost, and power consumption, multi-mode multi-band RF circuitry in such a device needs to be as simple, small, and efficient as is practical. Thus, there is a need for multi-mode multi-band RF circuitry in a multi-mode multi-band communications device that is low cost, small, simple, efficient, and meets performance requirements.